xi r 



PHYLUM CHORDATA 



440 



however, and a few Snakes are viviparous, the ova being 

 developed in the interior of the oviduct, and the young 

 reaching the exterior in the completely formed condition. 



FIG. 255. Section of the pineal eye of Hatteria punctata. g. blood-vessels ; h. 

 cavity of the eye filled with fluid ; k. capsule of connective tissue ; /. lens : in. 

 molecular layer of the retina ; r. retina ; st. stalk of the pineal eye ; x. cells in 

 the stalk. (From Wiedersheim, after Baldwin Spencer.) 



The Lizards are for the most part terrestrial animals, 

 usually extremely active in their movements and endowed 

 with keen senses. The majority readily ascend trees, and 



Man. Zool. G G 



